class testPrivate:
    def __init__(self, x, y):
        self.__x = x
        self.__y = y

    def add(self):
        self.__s = self.__x + self.__y
        return self.__s

    def printData(self):
        print(self.__s)


t = testPrivate(3, 5)
s = t.add()
t.printData()
print("s=", s)
